1. Field of the Invention
This invention relates to lithium niobate optical modulators. In particular, the invention relates to lithium niobate optical modulators with electrode structures enabling chirp parameters to be chosen and controlled; some forms of the invention also achieve operation at high frequencies (bit rates) of up to 40 GHz.
2. Background of the Related Art
As the demand for telecommunications services and bandwidth has boomed, the need for, and advantages of, external modulation in fibre-optic transmission systems has been firmly established. Lithium niobate is today one of the most important dielectric materials in the field of integrated optics, both for research and for technological applications. This importance is due to the strong correlation between the optical properties of the crystal, its refractive index, and the application of various kinds of external fields; namely electric fields (electro-optic effect), sound waves (acousto-optic effect) and electromagnetic waves. Lithium niobate external modulators provide both the required bandwidth and a means for mining the effects of dispersion that limit system performance.